Also known as: volitional test of mental incapacity · volitional tests for mental incapacity · irresistible impulse test · volitional prong
Written by attorneys · grounded in primary & secondary sources — see below
A standard for determining criminal insanity that excuses conduct when mental illness prevents the defendant from controlling actions or conforming conduct to the requirements of law. The inability to control need not arise suddenly and may develop or persist over time.
Virgil Volpe, a benefits clerk with severe depression and psychotic episodes, believed his supervisor persecuted him. Over several months an inner pressure built until he smashed office computers and records. Under the volitional test the jury credits expert testimony that his illness left him unable to resist the pressure and acquits him even though he understood the acts were wrong.
Vivian Vaughn, a construction foreman with a documented traumatic brain injury linked to impulse dysregulation, felt an urge to strike a subcontractor grow daily over weeks. After the subcontractor again questioned instructions, Vaughn seized a pipe and swung it. The volitional test permits acquittal because the illness produced an inability to control conduct that developed gradually rather than suddenly.
Select any source to read its text and confirm it supports the definition.
No. The test excuses a defendant whose mental illness prevents control over conduct or conformity to law even when the inability develops gradually or exists over time.
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No. Planning does not necessarily show retained control when mental illness destroys the capacity to resist the impulse. The test focuses on whether the illness eliminated the ability to conform conduct to law at the time of the act.
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The volitional test excuses inability to control conduct even when the defendant knows the act is wrong. M'Naghten requires a defect of reason that prevents knowing the nature or wrongfulness of the act.
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Yes. The test is satisfied when mental illness leaves the defendant unable to control actions or conform conduct to law. Expert evidence of that inability supports acquittal even if the defendant understood the conduct was illegal.
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…existing tests in the District of Columbia for determining criminal responsibility — the right-wrong test supplemented by the irresistible impulse test — are unsatisfactory and that a different test should be adopted on retrial. This contention has behind it a long history of agitation for reform, and substantial scholarly and official…